<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .title {
            font-size: 30px;
        }
        body{
            width: 100%;
            height: 100%;
            background-color: yellow;
        }
        #myDiv{
            background-color: red;
        }
    </style>
</head>
<body>
<div class="title">h5页面</div>
<button onclick="sendMessage()">发送消息给原生</button>
<div id="myDiv"></div>
</body>
</html>

<script>
    //需要接收端口
    var currentPort
    window.addEventListener("message",(event)=>{
        if(event.data =="trans_port"){
            currentPort = event.ports[0]
            
            //接收鸿蒙端发送的消息
            currentPort.onmessage=(event)=>{
                document.querySelector("#myDiv").innerText = event.data
            }
        }
    })

    function sendMessage(){
        if(currentPort){
            var obj = {"type":"alert", "message":"我是网页中的获取的数据"}
            //通过网页端的端口发送数据给鸿蒙端
            currentPort.postMessage(JSON.stringify(obj))
        }

    }
</script>